Ultra-Small Fe₃O₄ Nanoparticles Decorated WS₂ Nanosheets with Superior Electrochemical Properties for Supercapacitors.

Fe3O4 nanoparticles/WS2 nanosheets nanocomposite was successfully synthesized in this study by a one-step hydrothermal method. Three different contents of Fe3O4 in the nanocomposite were prepared by changing the quantity of FeCl3 center dot 6H(2)O, ascorbic acid and NaHCO3. Fe(3)O(4 )nanoparticles are about 3 nm in diameter and combined with WS2 to form stable heterojunctions, which are good for releasing the volume change of electrode materials in charge/discharge procedure. Because of the large theory capacitance of Fe3O4 nanoparticle, the specific capacitance of the Fe3O4 nanoparticles/WS2 nanosheets nanocomposites increase with increasing content of Fe3O4 nanoparticles. When the weight ratio for Fe3O4 nanoparticles to WS2 nanosheets is up to 8:10, the specific capacitances of the nanocomposite are 83.85 F g(-1) and 149.25 F g(-1) as the scanning rate at 20 mV s(-1) and the current density at 0.5 A g(-1), respectively. Both of them of Fe3O4 nanoparticles/WS2 nanosheets are as almost 7 times high as that of WS2 nanosheets under the same measurement condition. This work shows that the Fe3O4 nanoparticles/WS2 nanosheets nanocomposite will be a kind of potential electrode materials for supercapacitors.